雨后彩虹，十分壮丽．彩虹是太阳光传播过程中被空中水滴______而_爱下问搜题

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问题填空题

雨后彩虹，十分壮丽．彩虹是太阳光传播过程中被空中水滴______而产生的．这个现象可以由太阳光通过玻璃三棱镜的实验来解释．如图可知，通过三棱镜时红光的偏折程度比紫光要______（选填“大”或“小”）．

答案

（1）不同颜色的光的折射本领不同，所以经三棱镜后的偏折程度不同，所以白光经三棱镜后，光屏上自上而下出现了红、橙、黄、绿、蓝、靛、紫的色带．

（2）用红光和紫光平行于同一个凸透镜的主光轴射入，红光、紫光对凸透镜的焦距不相同．红色光对凸透镜的焦距大，这是因为红色光较紫色光偏折能力小．

故答案为：折射；小．

完形填空

完形填空阅读短文, 从每题所给选项中选出可以填入空白处的最佳选项。（共15小题；每小题1分，满分15分）
Peter’s job was to examine cars when they crossed the frontier（国境） to make sure that they were not smuggling(走私) anything into the country. Every evening he would see a factory worker coming 1 the hill towards the frontier, pushing a bike with a pile of goods(货物) of old straw on it. When the bike 2 the frontier, Peter would stop the man and 3 him take the straw off and untie（解开） it. Then he would examine the straw very 4 to see 5 he could find anything, then he would look in all the man’s pockets 6 he let him tie the straw again. The man would then put it on his bike and go off down the hill with it. Although Peter was always 7 to find gold or other valuable things hidden in the straw, he never found anything. He was sure the man was 8 something, but he was not 9 to think out what it could be.
Then one evening, after he had looked through the straw and emptied the worker’s pockets 10 usual, he 11 to him, “Listen, I know you are smuggling things 12 this frontier. Won’t you tell me what it is? I’m an old man, and today is my 13 day on the job. Tomorrow I’m going to retire(退休). I promise I shall not tell 14 if you tell me what you’ve been smuggling.” The worker did not say anything for 15 . Then he smiled, turned to Peter and said quietly, “Bikes.”

单项选择题

世界贸易组织的最终目标是实现（）

A.世界贸易标准化

B.各国利益均等化

C.世界贸易自由化

D.世界贸易稳定化